Anisotropic dynamics of a spin-orbit-coupled Bose-Einstein condensate
Authors: Martone GI., Li Y., Pitaevskii LP., Stringari S.
Autors Affiliation: Dipartimento di Fisica, Universita\’ di Trento and INO-CNR BEC Center, I-38123 Povo, Italy; Kapitza Institute for Physical Problems, RAS, Kosygina 2, 119334 Moscow, Russia
Abstract: By calculating the density response function we identify the excitation spectrum of a Bose-Einstein condensate with equal Rashba and Dresselhaus spin-orbit coupling. We find that the velocity of sound along the direction of spin-orbit coupling is deeply quenched and vanishes when one approaches the second-order phase transition between the plane-wave and the zero momentum quantum phases. We also point out the emergence of a roton minimum in the excitation spectrum for small values of the Raman coupling, providing the onset of the transition to the stripe phase. Our findings point out the occurrence of a strong anisotropy in the dynamic behavior of the gas. A hydrodynamic description accounting for the collective oscillations in both uniform and harmonically trapped gases is also derived.
Journal/Review: PHYSICAL REVIEW A
Volume: 86 (6) Pages from: 063621 to: 063621
More Information: Useful discussions with G. Ferrari, G. Lamporesi, T. Ozawa, and I. Spielman are acknowledged. This work has been supported by ERC through the QGBE grant.DOI: 10.1103/PhysRevA.86.063621Citations: 87data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-02-23References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here